Clock-synchronizing mechanism



April 22, 1924. 1,491,223

T. s. CASNER I CLOCK SYNCHRONIZING MECHANISM Filed Sept. 20, 1922 ZXIII/III Patented Apr. 22, 1924.

UNITED STATES PATENT oFFicE.

rnannnus STEPHENS cAsNEn, or rnam'rmnn, new

CLOGK- SYNGHRONIZING MECHANISM.

1 Application flied September 20, 191252.. Serial No. 589,448.

To all whom it may concern:

Be it known that I, THADDEUS STEPHENS CAsNnn, a citizen of the UnitedStates, and residing at Plainfield, county of Union,

State of New Jersey, have invented' certain.

utilized in correcting master or other clocks} by Hertzian wavestransmitted through space from a central station at which a standardtime piece is located. In my co Finding application Serial No.4'55,262,'filed arch 24, 1921, is disclosed an-apparatus forsynchronizing a master clock with the standard clock at Washington, D.C.,'the synchronizing mechanism associated with the clock being operatedby an electromechanical device which is in turn controlled by thewireless signals from the central station. 'The synchronizing means isoperated electrically and its controlling switch is closed at the properinstant by mechanism which becomes operative only upon receipt of apredetermined series or codes-of signals, such asthat sent outby thecentral station at Washington.

This switch controlling device is in reality a code reading apparatuswhich becomes operative only. upon receipt of the proper sequence ofsignals. It may be formed in different ways and the present inventionhas for its object the'provision of a device of this character formed asan attachment which can be connected to a wireless receiving set and aclock having a suitable synchronizing device and by means-of which acircuit through the synchronizing device will be closed and the clockcorrectedat the exact instant of noon each day.

One embodiment of the invention is illustrated in the accompanyingdrawing in g which cured thereto, which plate maybe of insulatingmaterial if desired or may be of brass :or other'conductin'gmetalprovidedthat the various current bearing members of the apparatusare insulated therefrom, so that short circuits do not occur.

- Theswitch controlling the circuit through the synchronizing mechanismof the master or other clock (not shown)- is indicated at S,Ythis switchhaving two flexible blades 12 and 13 the movement of both of which are Inecessary to effect the closing of the switch and the completion of thecircuit through the synchronizing device. The switch blades 12 and 13are of resilient material and are supported upon a block 14 of aninsulating substance, the wires 15 and 16 leading from these bladesrespectively to the clock synchronizing mechanism. In the operation ofcertain types of electro-mechanical synchronizing mechanisms it isdesirable that the switch controlling the same be closed GX-I actly atthe time set and then opened immediately so that the clock is correctedand immediately released, and is not retarded by the synchronizingmechanism. The mechanism controlling switch S is of this character, thatis, it is designed to'efi'ect the in stantaneous closing of the switchat the proper instant and immediately after to effeet the openingthereof.

The downturned end of switch blade 13 is adapted to be moved to theright from the position in which it is illustrated in Figure 1 to theposition'in which it is illustrated in Figure 2 by means of a segmentalcam 17 of insulating material, such as fiber or bakelite. This cam isrotatably mounted upon a short shaft 18 supported on the plate 11, thecam being freely rotatable upon the shaft but its movement being limitedby means of a pin 19 which works in the circular slot 20 in the cam,this pin being secured in wheel 21 which is also rotatably supportedupon shaft 18.

VVhee] 21 is provided the lowermost of which is normally in engagementwith a pin or stop 22 projecting laterally from the plate 11, a spring23 having one end fixed to the wheel and the other end to plate 11tending constantly to rotate wheel 21 in a counter clockwise directionto this limiting position. The angle subtended at the center of pin 18by the slot 20 is equal to the angle subtended by eight consecutiveteeth of wheel-21 and as this wheel is rotatwith eleven teeth 21 i thecam 17 downwardly to the position inwhich it is illustrated in Figure 2,the switch blade 13 being thereby'moved to the right. lrlovement ofwheel 21 through a lesser angle than that subtended by nine teeth willnot afiect the movement of switch blade 13 since pin 19 will not contactwith the end of slot 20 to move the cam.

Switch blade 12 is rigidly connected by means of a bar 24 of insulatingmatetial to the armature 25 of electromagnet 26, this armature beinpivotally mounted at 27 on the plate 11. lillectromagnet 26 is in alocal circuit 28 which is normally closed, the ma net 26 being thereforenormally'energized and switch blade 12 normally in the posi tion inwhich it is illustrated in Figure 1. Circuit 28 includes, however, thearmature 29 of an electromagnet 30, this armature being normally drawnto the right so that its free end is in contact with screw contact 31. Acoiled spring 32 retracts armature 29 to break circuit 28 wheneverelectromagnet is deenergized.

Electromagnet 30 is included in a circuit 33 which .is normally closedand which is controlled by a relay 34 of the :type described andillustrated in my copending application Serial No. 455,261, filed March24, $19.21. One member 35 of this relay is included in circuit 33 and isnormally in contact with adjusting screw 36' so that the circuit isclosed. The relay is connected by wires 37 to a wireless receiving setof-any well known type, and is designed and constructed to efiect amovement of member'35 away from screw 36 whenever an impulse is receivedby the receiving 'set. In other words, whenever an electrical impulse isreceived by the receiving set electromagnet 26 is" degenergized and'the' resilient switch blade 12 immediately moves armature 25 to theleft to the position shown iii'E-igure 2; Electromagnet 26 is, however,energized as soon as the wireless impulse is terminated.

Securely mounted upon plate 11 are electromagnets 40 which are in alocal circuit containing a switch (not shown) operated by the pendulumor escapement of theelock to be synchronized with the standard timepiece, this switch being closed once eachsec- 0nd by theclock. Armature41 pivotally supported vat 42 on plate 11 is positioned to be attractedby magnets 40 each time these magnets are energized and this armaturehas a horizontal arm to the end of which is pivotally connected a pawl43 acted on by a spring 44 to normally engage the toothed periphery ofwheel 21. \Vhen electromagnets 40 are energized, pawl 43 is raisedthrough a distance equal to that. between successive teeth of wheel 21and a succession of energizations and deenergizations of these magnetseffects a steady advance of wheel 21 in a clockwise direction, a dog 45normally drawn by a spring 46 against the toothed periphery of wheel 21preventing return movement of the wheel.

Ten movements of armature 41 will effect the advance of wheel 21 throughten teeth and, therefore, the movement of cam 17 and switch blade 13 tothe positions occupied by these members in Figure '2. Further advance ofwheel 21 can not take place inasmuch as there are no more teeth to beengaged by pawl 43. If dog 45 and pawl 43 are simultaneously moved byarmature 25 to releasewheel 21 after it has been rotated to the fullextent of its movement, the spring 23 acts to return it quickly toinitial position with its lowermost tooth abutting against stop 22.

The device above described is designed particularly for use inconnection with clocks to be synchronized in accordance with the signalssent out by wireless from Washington, as before mentioned. In "thissystem, signals are sent out at second intervals for the five ,min'utespreceding the noon'hour except that the twenty ninth second of eachminute is blank, and also the fifty fifth through the fifty ninth secondof each minute, exce'pt'the' lafstcminute, when the fiftieth through the'fi'fty ninth seconds are blank, the final dash being given on thesixtieth second. I

In the operation of the device thewireless is connected to relay 34 andthe magnets 40 are electrically connected to the clock escapement at.least several minutes before the noon signal, either manually or byautomatic means. The movement of thependuhim or escapement' causesenergization of magnets 40 at second intervals and the pawl 43 tends toadvance Wheel one tooth per second, Each secondgdiowever, an impulse isreceived by the wireless apparatus and magnet 26 is deenergized. Thisdeenerg-ization of magnet 26 results in the movement ofarxnature 25toward the left through the action of the spring contact blade 12 sothat pawl 43 and dog 45 are disengaged from wheel 21 at each second andthis wheel therefore falls back again to -starting position. i

At the close of each minute five secondimpulses of the wir eless areomitted, the magnet 26 remains. energized for fiv onds and wheel 21 isadvanced five teeth be fore magnet26 is again deenerg ized and the wheelreleased. During this rotation pin 19 travels toward the bottom of slot20 but not through a sufficient distance to operate cam 17. When,however, the end of the final minute is reached, magnet 26 will remainenergized for ten consecutive seconds and pawl 43 will advance. wheel 21ten teeth so that pin 19 strikes the lower end of slot 20 and moves cam17 into the position shown in Figure 2, moving blade 13 to the right.Upon the recei t by the wireless receiving set of the final noon signalmagnet 26 is again deenergized, armature 25 moves quickly to the leftand spring blade 12 makes a contact with blade 13 thereby closing switchS and actuating the clock synchronizing mechanism. Movement of thearmature 25 to the left of. course, throws out pawl 43 and dog 45 andreleases wheel 21. This wheel turns rapidly in a counter clockwisedirection'and, when pin 19 reaches the u per end of slot 20, moves cam17 upwardly to allow spring blade13 to move. to the left and to therebybreak the circuit through the synchronizin mechanism.

The synchronizing mechan sm 1s, there fore, energized only for aninstant and movement of the clock is not interfered with. InFigure 2 thearts are illustrated as they will be at the instant of the finaldeenergization of the electromagnet 26, contact having been establishedbetween blades 12 and 13 and wheel 21 having-been disengag'ed by pawl 43and dog 45 and ready to start its return movement to operate cam 17 Itsometimes happens that, due to thunderstorms or other electricaldisturbances,

the noon signals are interfered with and when such disturbances are ofconsiderable magnitude, as in case of summer thunderstorms, themechanism may fail to catch the noon signal. In such case a wheel havingsix teeth only instead of eleven may be substituted, so that theapparatus will func tion after five seconds of radio silenoeinstead often. This causes the mechanism, whenever the signals are accuratel received, to function five times instead 0. once and to correct the handsat the ends of the 56th, 57th, 58th, 59th and 60th minutes in steadof atthe end of the 60th minute, or at noon. only. Thuswhen the conditionsare such that the signals are received with difficulty the apparatus hasfive. chances of operating instead of one only. In this case theenergization of magnets 40 begins at min utes before the noon hour.

From the above description the operation of the device will be apparentto those skilled in the art. It may be made as a unit, as illustrated.and attached to clocks of various types having suitable synchronizingmechanism, or may be built into'the clock itself if 'found desirable. Itwill also be obvious that changes may also be made in the design andarrangement of parts and that-the invention is not limited in its scopeto that form herein disclosed by way of example.

Having thus described my inventionwhat is claimed as new and desired tobe secured by Letters Patent is:

1. In a device of the class described, in

combination, asupport, a switch on said support and adapted to close andopen a circuit through an electromechanicalclock synchronizing device,and means for opening and closing said switch, including a cam, arotatable member for operating the cam, and electromechanical devicesfor operating said rotatable member upon receipt of a series ofelectrical impulses in predetermined sequence,

2. In a device oft-he class described, in combination, a support, aswitch on said support, and means for openin and closing said switchincluding, a cam a apted to contact with' a movable switch member tooperate the same, a rotatable member operatively connected to the camfor actuating the same,

a spring for normally turning said rotatable member in one direction tomove the cam to inoperative position, an electromechanical device forrotating said rotatable member against the tension of said spring tothrow the cam into operative position upon receipt of a predeterminednumber of electrical impulses, and a second electromechanical device foreffecting the release of said rotatable member. 7 a

3. In a device of the class described, in combination, a support, ,aswitch on said support and adapted to close a circuit through anelectromechanical clock synchronizing device, and means for openingandclosing said switch including a cam, a member pivot'ally mounted on saidsupport for operating the cam, and devices for operating said pivotedmember upon receipt of a series of energizations in predeterminedsequence.

4. In a device of the class described, in combination, a support, aswitch on said support and adapted to close and open a .circuit throughan electromechanical clock through an electromechanical clock synchr0-nizing devie, and to be separated to open saidcircuit, and means foropening and closing said switch including electromechanical means formoving one switch member toward the other, a cam for moving the secondswitch member, and electromechanical means for operating said cam uponreceipt of a' series of electrical impulses in predetermined sequence.

6. Ina device of the class described, inv combination, a switch havingtwo flexible contact blades and controlling a circuit through anelectromechanical. clock synchronizing device, and electromechanicalmeans for bringing said switch blades into contact upon receipt of aseries of electrical impulses in predetermined sequence, both bladesbeing individually 'moved for the purpose set forth.

' In testimony whereof I hereunto afiix my 20 signature.

THADDEUS STEPHENS CASNER.

